Tripping mechanism for printing machines



E. W. GOODWIN TRIPPING MECHANISM FOR PRINTING MACHINES Aug. 8, 1950 Filed Oct. 18,- 1945' 3 Sheets-Sheet 1 PF ill I H IIIIIUHHIH :TI- im-ll 4 Au III-III I \L: 2, Iv MM J Aug. 8, 1950 E. w. GOODWIN 1 2,517,868

' TRIPPING MECHANISM FOR PRINTING MACHINES Filed 001;. 1a, 1945 s Shee ts-Sheet 2 A g- 8, 1950 E. w. GQODWIN 2,511,868

TRIPPING MECHANISM FOR PRINTING MACHINES Filed 001:. 18, 1945 3 Sheets-Sheet 3 1- 1 I J." I 68 l l It, v I a" llli i h V Him I |i||||||||||m 11W TOR.

I BY

Patented Aug. 8, 1950 TBIPPING MECHANISM FOR PRINTING MACHINES sdwin'w. Goodwin, New Rochelle, N. Y., assignor to R. Hoe & 00., Inc., New York, N. Y., a corporation of New York Application October 18, 1945, Serial No. 823,068

1 17 Claims.

This invention relates to printing, and-more particularly to an improved interrupter or trip" mechanism for use in a rotary printing machine.

The operation of sheet-fed lithographic printing machines has heretofore been controlled by detector devices and cooperable trip mechanisms. A sheet-detector device is usually located in the feed path along which sheets are successively fed to cooperating printing cylinders, and the detector controls the trip mechanism to insure that the printing operation of the machine is interrupted under certain conditions. If each sheet is fed in the usual manner along the feed path towards the printing cylinders, the sheet engages the detector and moves it to a position to lock the trip mechanism against operation, thus permitting the machine to continue to operate. However, if, through some inadvertence, a sheet is not fed along the feed path to engagement with the detector, then this detector remains in position to cause the trip mechanism to operate and thereby separate ortrip the printing cylinders, thus discontinuing the printing operation of the machine.

Existing trip mechanisms however, have proven dimcult to manufacture, and certain of their components are subjected to excessive wear. Furthermore their inherent constructions and arrangements cause parts to be placed outside the machine frames whereas they could more advantageously be positioned between the machine frames.

Therefore, an object of this invention is to provide an improved trip mechanism for use in a rotary printing machine having cooperable printing cylinders.

Another object of this invention is to provide an improved trip mechanism for use in a rotary sheet-fed printing machine having cooperable printing cylinders to which the sheets are successively fed along a path in which a detector device is operably located and cooperably associated with the trip mechanism.

A specific object of this invention is to provide an improved trip mechanism for use in a rotary sheet-fed printing machine, the trip mechanism including an oscillative trip shaft operably connected with cylinder tripping components, trip arms carried by the trip shaft, trip-operating links pivotally secured to the trip arms, and means actuated by operating components of the printing machine and selectively operable to engage a link to rock the trip shaft to either on" or o positions.

A more specific object of this invention is to provide an improved trip mechanism for a rotary sheet-fed printing machine having cooperating printing cylinders to which sheets are successively fed along a feed path in which a detector device is located. the trip mechanism including an oscillative trip shaft operably connected withpylinder tripping components, trip arms carried by the trip shaft, trip-operating links pivotally secured to the arms, means actuated by operating components of the printing machine and selectively operable to engage a link to rock the trip shaft to either "on or "off" position, and means operably associated with the detector device to control the operation of the said selectively operable means.

It is also an object of the invention to provide for use in a printing machine a trip mechanism of generally improved construction, whereby the device will be simple, durable and inexpensive in construction, as well as convenient, practical, serviceable and efficient in its use.

With the foregoing other objects in view, which will appear as the description proceeds, the invention resides in the combinations and arrangements of parts, and in the details of construction hereinafter described and claimed, it being understood that various changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

For a complete disclosure of the invention, a detail description thereof will now be given in connection with the accompanying drawings which illustrate a, preferred embodiment of the invention, wherein:

Fig. 1 is a fragmental side elevation of a lithographic offset printing machine showing the invention applied thereto;

Fig. 2 is an enlarged elevation of the improved trip operating mechanism;

Fig. 3 is a fragmental plan view of components of the device, the view being seen in the direction indicated by the arrow 3, in Fig. 2 and Fig. 4 is a fragmental sectional view taken on the line 4-4 of Fig. 2, as indicated by the arrows.

Referring to the drawings in which similar reference characters designate corresponding parts, there is depicted components of a. lithographic offset printing machine adapted to print on sheet metal, cardboard or other similar products. The machine includes a conventional frame I!) having opposed side members H which operably support an impression cylinder l2 and the cooperable blanket cylinder l3. Each cylinder is pro- 3 vided with a shaft that has its terminals rotatably supported in eccentric bearing members I2a and Ho respectively, which are rotatably received in aligned apertures formed in the side members I I of the machine frame, so that upon synchronous rotation of the eccentric bearing members, the cylinders are moved to and from printing position or off printing or trip position, in conformity with the usual practice which is well understood by those skilled in the art.

In the form illustrated. the aligned eccentric bearing members I3a of the blanket cylinder I3 are each pivotally connected at each side of the machine to an adjustable link I6, and the opposed terminals of these links are each pivotally connected to a lever II carried by a shaft I8. An operating lever I8 is secured to a terminal of the shaft I8, so that normal movement of the lever l9 about its fulcrum shaft I8 causes the links I6 to rotate the eccentric bearings I3a to move the blanket c linder I3 to and from printing and of!- printing positions.

The aligned eccentric bearings I2a of the impression c l nder I2 are pivotally secured to adjustable links 20, and the opposed terminal of each link is pivotally connected with a lever 2I which is secured to and rotates with a trip shaft 22. so that upon rotation of the trip shaft, the eccentric bearing members I2a will rotate to thereby move the impression cylinder I2 to and from printing and off-printing positions.

In the form illustrated, the trip shaft 22 is arranged to trip the impression cylinder I2, but it is to be understood that this trip shaft may be operably connected with other cylinders of the machine to thereby trip them in conformity with the usual practice.

The sheets are fed to the printing cylinders I2 and I3, along a feed path including a feed board 23. These sheets are conveved to the printing cylinders by pusher fingers 24 in conformity with the usual practice which is well understood by those skilled in the art.

The trip shaft 22 has a pair of spaced levers 25 and 25a (Figures 2 and 4) secured thereto within the side members II of the machine frame, and these levers each have opposed radially-extending arms 26 and 21 which are provided with holes (Figure 4) to receive the outer terminals of pins or shafts 3i and 32. A link 28 is pivotally secured to the arms 28 by the in or shaft 3|, 'and a link 30 is pivotally secured to the arms 21 by a similar pin or shaft 32. The pin 3| also receives a head 38 of a. rod14 which is surrounded by a helical extension spring 35. The outer terminal of the rod 34 passes through an aperture formed in a Inc or poppet 36 supported by a bracket 81 carried by the side members II of the machine frame. The spring 35 reacts between the lug 36 and the head 33 of the rod 34 to bias the trip shaft 22 toward either on or off printing positions, as will be hereinafter explained. oscillatory movement of the trip shaft 22 under the influence of the spring 35 is limited by adjustable stop screws 28 (Figure 2) which are engaged by the outer terminals of the arms 26 and 21. The stop screws 28 are supported by a machine frame component or bracket Ho. The bodies of the links 28 and 38 lie in the same vertical plane, and the inner edge of the body of each link is provided with a guide surface 38 having an upstanding shoulder or abutment face 48 at one terminal thereof, for a purpose to be here- "inafter'explained. The inner terminals of the links are laterally offset In opposite directions,

(Figure 4) and the offset portion H of each link is provided with an elongated slot 42. Each laterally offset portion ll of each link is laterally enlarged at each side of the slot to provide opposed guide surfaces 43, for a purpose to be hereinafter set forth.

A trip-operating lever 45 (Figure 2) is pivotally supported at its upper terminal by a transversely extending shaft 46 which is secured to the side members II of the machine frame. The lower terminal of the trip operating lever 45 is bifurcated (Fig. 4) and straddles the inner terminal of a trip operating pawl 41. A pin 48 extends through aligned apertures formed in the furcations of the lower terminal of the trip operating lever 45, and through an aperture 5!) formed in the inner terminal of the trip operating pawl or thrust member 41. Rollers 5| (Figure 4) are rotatably supported on the pin 48 between the outer faces of the trip operating lever furcations and spaced washers 52, the washers being retained against outward axial movement by pins or cotters 53. Each roller 5| is operably received in a slot 42 of the offset portion 4| of each trip operating link, thereby supporting the outer terminals of the links in operable position. The pawl 41 lies in the same vertical plane as the body portions of the links 28 and 30, and the outer terminal of this pawl is enlarged (Fig. 2) in directions towards the links 28 and 30, and the enlarged portion has opposed guide surfaces 55 and 56 and an end surface or shoulder 51.

A bifurcated member or stirrup 58 straddles the link 28 and the pawl 41, and the lower terminal of the stirrup 58 is pivotally secured to the pawl, as indicated at 68. The upper terminal of the stirrup 58 has a rod 6| extending outwardly therefrom, and this rod passes through an aperture formed in a lug or poppet 62 carried by the outer terminal of an arm 63 of a selector lever 65. A helical spring 66 surrounds the rod H and is interposed between the stirrup 58 and the poppet 62 and reacts to force the outer terminal of the arm 63 against lock nuts 61 threadedly secured to the rod 6I. The elector lever 65 has its intermediate portion fulcrumed to a bracket 68 (Fig. 3 of the machine frame by stub shaft I8 which extends through aligned apertures formed in a hub II of the selector lever 65, the bracket 68 and in a laterally enlarged inner terminal of a latch arm 12 (Figs. 2 and 3). An arm I5 extends inwardly from the hub II of the selector lever 65 and has a tie pin 16 rigidly secured to its outer terminal, and this pin is also rigidly secured to the latch arm I2, thereby causing the selector lever arm 15 and the latch arm 12 to move in unison. A roller TI is pivotally secured to the outer terminal of the arm I5 of the selector lever 65, and this roller reacts with a selectoroperating cam I8 carried by cam shaft which is driven in timed relation with the printing cylinders, the shaft 80 rotating once for each revolution of the impression cylinder I2.

The cam shaft 88 supports a trip-operating cam 8I which is operably engaged by a roller 82 pivotally supported on the trip-operating lever 45. The cam shaft 88 also carries a latch-operating cam 88 which is operably engaged by roller 85 rotatably supported on a latch lever 86 which is pivotally secured to a bracket of the machine frame, as indicated at 81. An arm 88 of the latch lever 86 is pivotally connected with a link 88, and this link is in turn pivotally connected with a short arm 8| of a bell crank lever 82 which is fillcr med to the machine frame, as indicated at 88 -of the machine frame. A helical extension spring 88 surrounds the outer terminal of the rod 88 and reacts to force the rod 08 and long arm 85 of the bell crank lever outwardly, thereby normally holding the latch lever roller 85 against the latch operating cam 83, for a purpose to be hereinafter explained.

The outer terminal of the bell crank lever arm 95 has one terminal of a trip bar I pivotally secured thereto, and the opposed terminal of this bar is slidably mounted on a pin IOI which engages a slot formed in the outer terminal of the trip bar I00, so that rotation of the latch operating cam 83 will cause the trip bar I00 to reciprocate. A stop member I02 forms one terminal of a bell crank I03 which is pivotally supported adjacent the feed board, and the opposed arm I04 of the bell crank provides a detector finger I08. The outer terminal of the detector finger I08 normally extends above the feed board a and lies in the path of travel of a sheet moving towards the printing cylinders along the feed board. When the bell crank I02 is in its normal position. as depicted in dotted lines in Fig. 1, it locates the stop member I02 in the path of outward movement of the reciprocatory trip bar I00, for a purpose to be hereinafter explained.

The trip-operating lever 45 (Fig. 2), has a rod I01 pivotally secured thereto, and'the outer terminal of this rod is slidable in an aperture formed in a lug or poppet I08 upported by the machine frame. A helical extension spring H0 surrounds the rod and reacts against the. poppet and a washer carried by the rod to force the trip-operating lever roller 82 in operable engagement with the cam surface of the trip-operating cam 8|.

The selector lever 85 has a rod III pivotally secured to its arm 83, as indicated at 2, and this rod extends through an aperture formed in a machine frame bracket II3 (Figures 1 and 2). A helical extension spring II5 surrounds the rod and reacts between the brackets I I3 and a washer H6 carried by the rod to normally force the selector lever roller 11 against the selector-operating cam 18.

In operation, as the printing cylinders I2 and I8 rotate, the trip-operating cam 8|, the selector operating cam 18 and the latch operating cam 83 rotate in timed relation therewith. As the trip-- operating cam 8I rotates, it imparts oscillatory movement to the trip-operating lever 45 which, in turn, imparts reciprocatory movement to the trip-operating pawl 41. Rotation of the selector operating cam 18 rocks the selector lever 85 about its fulcrum shaft 10, if the movement of the selector lever 85 is not impeded by the latch lever 86. If a sheet to be printed is traveling under usual conditions along the feed board 23 toward the printing cylinders, the latch lever 88 is permitted to drop to engagement with the low part of the latch operating cam 83, because the stop member I02 of the detector mechanism is positioned, by the engagement of the sheet with the detector finger I08, out of the path of travel of the trip bar I00 (Fig. 1). Now the outer terminal of the latch lever 88 lies under the outer terminal of the latch arm I2, thus preventing the selector lever roller 11 from dropping to engagement with the low portion of the selector operating cam 18. In this position, the outer terminal of the trip-actuating pawl 41 engages the shoulder formed on the trip-operating link 80,

- the printing operating of the machine.

and as the pawl reciprocates under the influence of the trip-operating cam 8|, the trip shaft 22 is moved to, or maintained in, printing position, as shownin Fig. 2. However, if a sheet is not fed in the usual manner along the feed board 28, then the detector finger I08 extends above the feed board and positions the stop member I02 in the path of outward movement of the tripping bar I00. This prevents the latch roller 85 from dropping to the low part of the latch-operating cam 88, so that the selector lever roller 11 is free to engage the low portion of the selector-operating cam I8, thereby moving the outer terminal of the pawl 41 into engagement with the shoulder 40 of the trip-operating link 28, so that upon reciprocation of this pawl by rotation of the tripoperating cam 8|, the trip shaft 22 is oscillated in counter-clockwise direction until this oscillatory movement is limited by the engagement of the uper stop screws 29.with the arm 26. This movement of the trip shaft 22 moves the impression cylinder to trip position by movement of the operably interposed eccentric bearing members I2a., links 20 and levers 2|, thus discontinuing However, when a sheet is again fed to the cylinders in normal manner, the components of the mechanism are reset during the next rotation of the cam shaft 80, the trip shaft 22 then being turned to move the printing cylinder to printing position.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the claims rather than to the foregoing description for an indication of the scope of the invention.

What I claim is:

1. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in.printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and oif-printing position; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and having an abutment face spaced from the pivotal connection, and a thrust member actuated by an operating component of the printing machine to selectively engage the abutment face of either link and move it, thereby moving the cylinder to either printing or off-printing position.

2. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and havingan abutment face spaced from the pivotal con- I nection, and a thrust member actuated by a component of the printing machine which operates in timed relation'with the printing cylinders to selectively engage the abutment face of either link and move it, thereby moving the cylinder to either printing or ofl-printing position.

3. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from the printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and having an abutment face spaced from the pivotal connection, and a thrust member actuated by operating components of the printing machine to selectively engage the abutment face of either link and move it, thereby moving the cylinder to either printing or off-printing position.

4. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from the printing position in oil-printing position, an oscillative tripshaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and having an abutment face spaced from the pivotal connection, and a thrust member actuated by a component of the printing machine which operates in timed relation with the printing cylinders to selectively engage the abutment face of either link and move it, thereby moving the cylinder to either printing or off-printing position.

5. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and having an abutment face spaced from the pivotal connection, and a pivotally-supported thrust member actuated by a component of the printing machine which operates in timed relation with the printing cylinders to selectively engage the abutment face of either link and move it, thereby moving the cylinder to either printing or of!- printing position.

6. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft,

and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing position; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with with a trip arm and having an abutment face spaced from the pivotal connection, a tripoperating lever movable about a fulcrum and actuated by a machine component which operates in timed relation with the printing cylinders, and a thrust member pivotally connected to the lever and movable therewith, the thrust member being movable about its pivotal connection to selectively engage the abutment face of either link and move it, thereby moving the cylinder t either printing or off-printing position.

7. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of arms carried by and extending radially in opposite directions from the trip shaft, a pair of trip.

operating links each having one terminal pivotally connected to the outer terminal of an arm and having an abutment face spaced from the pivotal connection, a lever movable about a fulcrum and actuated by a machine component which operates in timed relation with the printing cylinders, and a pawl having one terminal pivotally connected to and movable with the lever whereby reciprocatory movement towards and away from the trip shaft is imparted to the pawl, the opposed terminal of the pawl being movable about its pivotal connection with the lever and between the trip-operating links to selectively engage the abutment face of either link and op rably move a link towards the trip shaft thereby moving the cylinder to either printing or off-printing position.

8. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions: the combination therewith of arms carried by and extending radially in opposite directions from the trip shaft, opposed trip-operating links each having one terminal pivotally secured to the outer terminal of each arm and having an elongated slot formed in its opposed terminal, a lever movable about a fulcrum and actuated by a machine component which operates in timed relation with a printing cylinder, a pawl having one terminal pivotally connected and movable with the lever whereby reciprocatory movement towards and. away from the trip shaft is imparted to the pawl, the opposed terminal of the pawl being movable about its pivotal connection with the lever and between the tripoperating links to selectively engage and operably move a link towards the trip shaft thereby moving the cylinder to either printing or of!- printing position, and roller means supported by the lever and received within the slots formed in the links.

9. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support 9, cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of arms carried by and extending radially in opposite directions from the trip shaft, opposed trip-operating links each having one terminal pivotally secured to the outer terminal of each arm and having an elongated slot formed in its opposed terminal, a shoulder formed on each link, a lever movable about a fulcrum and actuated by a machine component which operates in timed relation with a printing cylinder, a pawl having one terminal pivotally connected and movable with the lever whereby reciprocatory movement towards and away from the trip shaft is imparted to the pawl, the opposed terminal of the pawl being movable about its pivotal connection with the lever and between the trip-operating links to selectively engage a shoulder on a link and operably move the engaged link towards the trip shaft thereby moving the cylinder to either printing or off-printing position, and rollers supported in axial alignment by the lever and received within the slots formed in the links.

10. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and having an abutment face spaced from the pivotal connection, and a thrust member actuated by an operating component of the printing machine in timed relation with the printing cylinders, a sheet detector mechanism, and selector means actuated by an operating component of the printing machine in timed relation with the printing cylinders and cooperable with the sheet-detector mechanism to move the thrust member to operable engagement with a selected link whereby the link is operably moved to thereby move the cylinder to either printing or off-printing position.

11. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printingposition and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, andmeans for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and ofl-printing positions the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm andhaving an abutment face spaced from the pivotal connection, a trip-operating pawl formed to selec tively engage the abutment face of either link and actuated by an'operating component of the printing machine in timed relation with the printing cylinders, sheet-detector mechanism, and selector means actuated by an operating component of the printing machine in timed relation with the printing cylinders and cooperable with the sheet-detector mechanism to move the thrust member into operable engagement with the abutment face of one link to move the cylinder to printing position, or into operable en a ement with the other link to move the cylinder to offprinting position.

12. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support-the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each.

printing cylinders, sheet-detector mechanism,

and selector means actuated by an operating component of the printing machine in timed relation with the printing cylinders and cooperable with the sheet-detector mechanism to move the pawl to operable engagement with the abutment face of a selected link, whereby the link is operably moved to thereby move the cylinder to either printing or off-printing position.

13. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in print ing position and movable to support the cylinder at a location removed from printing position in off-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with a trip arm and having an abutment face spaced from the pivotal connection, a trip-operating lever movable about a fulcrum and actuated by a component of the printing machine which operates in timed relation with the printing cylinders, a pawl pivotally connected to the lever and operably movable therewith, sheet-detector mechanism, and selector means actuated by an operating component of the printing machine in timed relation with the printing cylinders and cooperable with the sheet-detector mechanism to move the pawl about its pivotal connection to operable engagement with the abutment face of a selected link whereby the link is operably moved by the movement of the trip-operating lever and pawl to 11 thereby move the cylinder to either printing or off-printing position.

14. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in oiI-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and oil-printing positions; the combination therewith of trip arms carried by and extending radially from the trip shaft, a pair of trip-operating links each pivotally connected with one of the arms and each link having an abutment face spaced from the pivotal connection, a trip-operating lever movable about a fulcrum and actuated by a component of the printing machine which operates in timed relation with the printing cylinders, a pawl having its inner terminal pivotally connected to the trip-operating lever and movable therewith, and the outer terminal of the pawl being movable between the links about its pivotal connection with the trip-operating lever, sheetdetector mechanism, and selector means actuated by an operating component of the printing machine in timed relation with the printing cylinders and cooperable with the sheet detectormechanism to move the outer terminal of the pawl to operable engagement with the abutment face of a selected link whereby the link is operably moved by the movement of the trip-operating lever and pawl to thereby move the cylinder to either printing or off-printing position.

15. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in oil-printing position, an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and oif-printing positions; the combination therewith of arms carried by and extending radially in opposite directions from the trip shaft, a pair of trip operating links each having one terminal pivotally connected to a terminal of an arm and each having an abutment face spaced from the pivotal connection, a lever movable about a fulcrum and actuated by a machine component which operates in timed relation with the printing cylinders, a pawl having one terminal pivotally connected and movable with the lever whereby reciprocatory movement towards and away from the trip shaft is imparted to the pawl, the opposed terminal of the pawl being movable about its pivotal connection with the lever and between the trip-operating links, sheet-detector mechanism, and selector mechanism actuated by an operating component of the printing machine in timed relation with the printing cylinders, and cooperable with the sheet-detector mechanism to move the pawl about its pivotal connection to operable engagement with the abutment face of a selected link whereby the engaged link is operably moved by the movement ofthe trip-operat- .ing lever and the pawl to thereby move the cylinder to either printing or off-printing position.

16. In a printing machine having cooperable printing cylinders, cylinder-supporting members arranged to operably support a cylinder in printing position and movable to support the cylinder at a location removed from printing position in oiI-printing position,. an oscillative trip shaft, and means for operably connecting the trip shaft with the cylinder-supporting members whereby oscillatory movement of the trip shaft moves the cylinder to and from printing and off-printing positions; the combination therewith of arms carried by and extending radially in opposite directions from the trip shaft, a pair of trip operating links each having one terminal pivotally connected to the outer terminal of warm and a slot formed in its opposed terminal and each having an abutment face spaced from the pivotal connection, a lever mounted for oscillatory movement about a fulcrum and actuated by a machine component which operates in timed relation with the printing eylinders,a pawl having one terminal connected to and movable with the lever whereby reciprocatory movement towards and away from the trip shaft is imparted tothe pawl, the opposed terminal of the pawl being movable about its pivotal connection with the lever and between the trip-operating links, sheet-detector mechanism, and a selector mechanism actuated by an operating component of the printing machine in timed relation with the printing cylinders, and cooperable with the sheet-detector mechanism to move the pawl about its pivotal connection with the lever to operable engagement with the abutment face of a selected link whereby the engaged link is operably moved by ders into and out of printing relation with the other and having an oscillatable trip shaft for moving the bearings, a cam operated member for moving the shaft selectively in either direction, and a sheet detector mechanism; the combination therewith of a lever secured to the shaft and having oppositely extending trip arms, a pair of links each pivotally connected at one end to a trip arm and having a slot at the oppo-' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,874,013 Kaddeland Aug. 30, 1932 2,121,195 Harrold et al June 21, 1938 2,356,058 Hunting Aug. 15, 1944 2,356,315 Gudger Aug. 22, 1944 2,392,391 Kaddeland Jan. 8, 1946 

